Rare Case of Merkel Cell Carcinoma Associated With CLL
Posted: Monday, September 13, 2021
Sepideh Karkon-Shayan, MD, of the Gonabad University of Medical Sciences, Iran, and colleagues presented a rare case of Merkel cell carcinoma in an unconventional site—the right calf—that was associated with chronic lymphocytic leukemia (CLL) in Clinical Case Reports. These findings suggest that physicians should be aware of atypical Merkel cell carcinoma lesions to achieve effective management of such cases.
A 69-year-old man presented with a single 3.5 × 3.5 × 1.5 cm lesion on the inside of his right calf, which caused discomfort and grew threefold within the past month. Despite the lesion being relatively painless, it exhibited a pigmented papillomatosis surface, was nonhemorrhagic and nonpruritic, and did not have any smell or secretions. The patient’s medical history included seborrheic keratosis and basal cell carcinoma.
Biopsy of a 2 × 3 mm section with a 1-cm healthy margin revealed an orthokeratotic epidermis, a high nucleus-to-cytoplasm ratio, and hyperchromatic nuclei. Immunohistochemistry staining ruled out thyroid malignancies, melanoma, and B-cell lymphoma, as it was negative for S100 protein, transcription termination factor-1, and B-lymphocyte antigen protein. A peripheral blood smear demonstrated smudge cells, indicating lymphoproliferative disorders following CLL. Immunophenotyping noted positivity of markers CD5, CD19, CD20, and CD23, suggesting B-cell type CLL.
A right-groin ultrasound showed lymph nodes with a hypervascular and thick cortex with central and peripheral vascular flow, indicative of malignancy. A total of 45 lymph nodes were removed, and biopsy revealed Merkel cell carcinoma. The clinical stage of this lesion was determined as stage IV, so the patient was administered chemotherapy. A CT scan 3 months later identified multiple adenopathies and 90 prominent lymph nodes, along with scattered sclerotic lesions. The patient died 9 months later despite treatment and procedures.
Disclosure: The study authors reported no conflicts of interest.